Sentences with phrase «20th century warming»

You will find this figure illuminating; the spread is far greater than 20th century warming: https://curryja.files.wordpress.com/2013/07/presentation1.jpg

How much 20th century warming was quite natural?

The «scientific consensus» that late 20th century warming can be attributed to human activity is routinely confused with the putative consequences of climate change — particularly social effects — and the political arguments for climate change mitigation.

RIE If you are enlightened in the chaotic dynamics of Kolmogorov and of Hamiltonians, then when will the penny drop that 20th century warming might be an internal chaotic fluctuation?

What satellite data there is suggests a dominant role for cloud radiative effects — associated with the Pacific state — in late 20th century warming.

You would be 100 years to late to catch the 20th century warming but data could be collected for most of the 21st century.

Some of the late 20th century warming is therefore from a solar heat lag from the increase in solar output from 1750 - 1950 +, meaning C02 effect is even weaker than in your paper above.

I struggle to see much of a difference between early 20th century warming and late 20th century warming.

taking them into account will decrease the simulated warming and may result in a mismatch between simulated and observed 20th century warming.

I have not much clue about the earlier 20th century warming — TSI is not an explanation.

If you like the late 20th century warming trend is like the curved ramp at the end of British aircraft carriers.

But then the 20th century warming would be insignificant, making the sceptics happier.

Since those earliest temperatures are merely modeled from data presumably collected elsewhere, early temperatures are susceptible to the «modeling whim du jour» and in this case the 2015 model had created a steeper 20th century warming trend in just 2 years.

It appears to me that a majority of 20th century warming was natural (overstated at that because of unwarranted adjustments to the data) and that the net feedback to rising atmospheric CO2 is negative.

... the early 20th century warming was due primarily due to solar forcings and a volcanic lull.

Most of the 20th century warming was natural.

«Some other models like CESM1 did include microphysics and an indirect aerosol effect, and had slightly lower 20th Century warming than observed... yet its climate sensitivity is higher than for [some other models that don't include the indirect aerosol effect]... the [GWPF] comment presumes that models have been tuned to reproduce the 20th Century temperature record, but this is mostly not true»

My main point was that a large internal warming contribution to late 20th century warming is unwarranted because it's contradicted by the physical data as described above.

Conventional thought is that the warming sun and reduced volcanic activity caused much of the early 20th Century warming.

For instance, sc 21 and 22 were short cycles (strong) and they caused the late 20th century warming.

Of course, if one accepts the conclusions of several solar studies that around 50 % (rather than 7 %) of the 20th century warming can be attributed to the unusually high level of solar activity (highest in several thousand years)-- most of which occurred in the first half of the century — then the 2xCO2 impact would only be ~ 0.8 C.

If you mean the «late 20th century warming trend» (1951 to 2000), I'd agree that a part of this warming may well have been due to GHGs.

Oceanic oscillations suffice to explain late 20th Century warming.

Government scientists made the magical transition from «no 20th century warming» to «unprecedented 20th century warming» — in just one decade.

We find several studies by solar scientists, which all conclude that around 50 % of the 20th century warming (versus only 7 %, as assumed by IPCC) can be attributed to the unusually high level of solar activity (highest in several thousand years).

«I see nothing in this chart that is inconsistent with the hypothesis that the sun might have been responsible for perhaps half of the 20th century warming» — what, the fact that whether the 11 year average sunspot count is going up or down bearing little or no resemblance to whether the temperature goes up or down doesn't seem inconsistent to you?

They rather like that early 20th century warming so they have no desire to see it reduced or plant doubt in people's minds that maybe it didn't happen.

Tamino at Open Mind examines the role of volcanic forcing (or lack thereof) in early 20th Century warming in Volcanic Lull.

The 20th century warming was beneficial to the tune of trillions of dollars, not harmful.

Does this mean that solar activity is also primarily responsible for late 20th century warming?

The second category relating to proxy reconstructions are the basis for the conclusion that 20th century warming is unprecedented.

Notice how skeptics always question late 20th century warming, but never early 20th century warming.

«The 20th century warming (IPCC 2007) is apparent to different extents in most, but far from all, records.

The full extent of the early 20th century warming can not be explained without it.

Note that I research and illustrate the late 20th Century warming period for a number of reasons.

«The revealing of the 20th Century warming hoax follows the earlier debunking of the Hockey Stick by Steve McIntyre and Ross McKitrick.

An international team of tree ring experts reported «No current tree ring based reconstruction of extratropical Northern Hemisphere temperatures that extends into the 1990s captures the full range of late 20th century warming observed in the instrumental record.»

Earth's surface temperature are largely driven by variations in solar activity, which may have contributed as much as 66 % of the observed 20th century warming.

All we know clearly is that CO2 doesn't appear to have been a significant factor in the early 20th Century warming period, but does appear to be at least a significant factor in the warming between 1970 and around 2000.

But natural ocean oscillations have also raised temperatures, and regards to understanding both 20th century warming events in the Arctic, ocean oscillations offer the superior explanation.

Well, no, not in the early 20th Century warming, but then, yes, in the late 20th Century warming.

They concluded that about one third of the 20th century warming (0.27 °C) was caused by urbanization and other land use changes.7

-LSB-...] it seems to me that by weighting the solar irradiance more strongly in the models, then much of the 19th to mid 20th century warming can be explained from the sun alone.

Yet, it is still a widely accepted myth for periods since 1980 - that human CO2 has caused unprecedented temperature increases, far outpacing any previous 20th century warming increases.

«Quantifying the role of solar radiative forcing over the 20th century -LSB-...] However, we also find that the largest contribution to the 20th century warming comes from anthropogenic sources.»

And, so correspondingly, the conclusion that half of the late 20th century warming was from GHGs is hardly likely to be supported once taking into account the above, especially since generally non-fudged temperature data has much less warming to account for in the first place.

A substantial concern for me when preparing my initial Model description was that for the sequence of events to be true the cooling of the stratosphere during the late 20th century warming period had to be natural without needing to invoke human CO2 or CFCs.

The above paper refers to the late 20th century warming period when the stratosphere was cooling and ozone was falling.

Without good information on what drove 20th century warming (and we don't have good information on what drove 20th century warming) it is hard to predict if temperatures are going up, down, or sideways.

One does not have to be a climate «rocket» scientist to recognize that the earlier 20th century warming increase was greater than the modern warming.